New administrator configuration

Is it possible to set up administrator accounts that have control over only one specific extension, or a small group of extensions? I’ve tried setting up a new administrator, restricting the range of extensions, and restricting their permissions via the “Admin Access” list, but they are still able to make changes outside of those permissions. I’m not sure if this is a bug or not.

Example, a test admin account is restricted to a single extension and has general settings, extension, and voicemail admin selected from the admin access list. This user is still able to alter the global fax configuration.

What we’d like to do ideally is allow certain users to have more fine-grained control over their accounts; say to define inbound routes, extensions, and ring groups to control their call flow. Essentially, we’d like to open up only a subset of features. Is this at all possible through FreePBX?